The present invention relates to a system and method for measuring and/or detecting the width of media, such as photosensitive paper, and an imaging apparatus such as a photographic printer which uses the media width detecting system.
Currently, photographic printers are capable of utilizing multiple paper widths. However, these printers do not provide for a convenient and accurate system for communicating the paper width to the printer as new unexposed rolls of paper are placed into the printer. Some printers rely on a person that operates the machine to input the paper width manually, either via a computer interface or setting switches or dials. Other printers utilize switches or magnets that are part of an input paper cassette magazine where the switches are set by the person operating the printer. Finally, it is known that an array of discrete sensors, often photo-optic, can be used to directly measure the width of paper without operator intervention.
In the case where an array of discrete sensors are used to directly measure the paper width without operator intervention, the sensors are physically placed on the paper track such that they detect the popular widths of photosensitive paper. However, when using a discrete array of sensors, one edge of the paper being measured is required to be geometrically known. In other words, one paper edge must be located against a guide of known location from the sensor array. Without this reference edge, the true paper width cannot be accurately measured.
The present invention provides for an improved system and method for measuring an absolute width of media, such as paper photosensitive film, photographic paper, cut sheets, a web, etc., without the need for human intervention and/or without the need for the paper to be referenced against a known location or guide. To accomplish the measurement without a reference and known location of a paper guide or edge, the paper and any location in a paper tracking mechanism is measured from one edge to the other. The present invention provides for an accurate and simple mechanism that detects both edges and the span therebetween.
In a feature of the present invention, a media width detecting system uses a measuring pattern which, for example, can be a plurality of bars placed across the width of the paper track. The bars can be either permanently placed or be in the form of a sticker or label placed across the width of the paper track. The bars can be spaced at known intervals or can be at variable intervals depending on the method of measuring. When media such as photosensitive paper is placed in the paper track, a subset of the bars are physically covered up or blocked. By using a reader in the form of, for example, an optical scanner, the number of uncovered and covered bars can be easily computed. From this, the paper width can then be determined.
The present invention provides for a media width detecting system that comprises a measuring pattern provided across a width of a media path; a reader positioned to view a full width of the measuring pattern, wherein media in the media path that traverses the measuring pattern blocks or covers up a portion of the measuring pattern from being viewed by the reader and leaves other portions of the measuring pattern exposed for viewing by the reader; and a computing device operationally associated with the reader that determines a width of the media traversing the measuring pattern based on a difference between the full width of the measuring pattern and a width of the other portions of the measuring pattern left exposed for viewing by the reader when the media traverses the measuring pattern.
Within the context of the present invention, the description with respect to the computing device being operationally associated with the reader refers to the fact that the present invention can provide for a computing device separate from the reader and integrated into the hardware of the imaging apparatus that is processing the media, a computing device separate from both the reader and imaging apparatus and connected to both, or a computing device integrated into the reader.
The present invention further provides for a media width detecting system that comprises a bar code pattern including a predetermined number X of total bars provided at intervals on a media path so as to extend along a width of the media path; a reader provided relative to the media path so as to view an entire width of the bar code pattern, wherein the media in the media path that traverses the bar code pattern provides for a first number N of uncovered bars on one side or both sides of the media that can be read by the reader; and a computing device operationally associated with the reader that computes a second number W of bars covered by the media traversing the bar code pattern based on a difference between the predetermined number X of total bars and the first number N of uncovered bars to determine a width of the media transversing the bar code pattern.
The present invention further relates to a media width detecting system that comprises a measuring pattern; a reader positioned to view the measuring pattern, wherein media that traverses the measuring pattern blocks a portion of the measuring pattern from being viewed by the reader; and a computing device operationally associated with the reader that determines a width of the media traversing the measuring pattern based on at least a width of the portion of the measuring pattern blocked by the media traversing the measuring pattern.
The present invention further relates to a media size detecting system that comprises a first measuring pattern provided across a width of a media path; a second measuring pattern provided on the media path so as to extend along a longitudinal direction of the media path; and a reader adapted to read the first measuring pattern to determine a width of media traversing the first measuring pattern, and read the second measuring pattern to determine a length of media traversing the second measuring pattern.
The present invention further relates to a method of measuring a size of media being conveyed along a media path which comprises providing a first measuring pattern across a width of the media path; positioning a reader relative to the media path so as to view a full width of the first measuring pattern; and determining a width of media in the media path which traverses the first measuring pattern based on at least a width of a portion of the first measuring pattern which is blocked from being viewed by the reader by the media traversing the first measuring pattern.
The present invention further relates to a printing apparatus that comprises a media supply section having at least one media entry opening for the passage of media therethrough; a printing section adapted to accept media from the media supply section; a media path for the passage of media from the media supply section to the printing section; and a media width detecting system positioned on the media path. The media width detecting system comprises a measuring pattern provided across a width of a media path; a reader positioned relative to the media path to view the measuring pattern, wherein media in the media path that traverses the measuring pattern blocks a portion of the measuring pattern from being viewed by the reader; and a computing device operationally associated with the reader that determines a width of the media traversing the measuring pattern based on at least a width of the portion of the measuring pattern blocked by the media traversing the measuring pattern.
The present invention further relates to a printing apparatus that comprises a media supply section that has at least one media entry opening for the passage of media therethrough; at least one media supply cassette having a media supply roll therein and positioned at the at least one media entry opening to supply media to the media supply section; a printing section adapted to accept media from the media supply section; and a media width detecting system positioned at an exit of the at least one media supply cassette. The media width detecting system comprises a measuring pattern positioned on a media path at the exit; a reader positioned to view the measuring pattern, wherein media which traverses the measuring pattern blocks a portion of the measuring pattern from being viewed by the reader; and a computing device operationally associated with the reader that determines a width of the media traversing the measuring pattern based on at least a width of the portion of the measuring pattern blocked by the media traversing the measuring pattern.
The present invention further relates to a media width detecting system that comprises a measuring pattern; and a reader positioned to view the measuring pattern, wherein media that traverses the measuring pattern blocks a portion of the measuring pattern from being viewed by the reader, and a width of the media traversing the measuring pattern is determined based on at least a width of the portion of the measuring pattern blocked by the media traversing the measuring pattern.
The present invention further relates to a printing apparatus that comprises a media supply section having at least one media entry opening for the passage of media therethrough; a printing section adapted to accept media from the media supply section; a media path for the passage of media from the media supply section to the printing section; and a media width detecting system positioned on the media path. The media width detecting system comprises a measuring pattern provided across a width of the media path; and a reader positioned relative to the media path to view the measuring pattern, wherein media in the media path that traverses the measuring path blocks a portion of the measuring pattern from being viewed by the reader, and a width of the media traversing the measuring pattern is measured based on at least a width of the portion of the measuring pattern blocked by the media traversing the measuring pattern.